Friction absorbing device



1:. M. LIGHT FRICTION ABSORBING DEVICE Dec. 29, 1942.

Filed'Dec. 15-, 1938 4 Sheets-Sheet l INVENTOR.

fiauzdfllgfzt,

ATTORNEY.

Dec. 29, 19420 D. M. LIGHT 2,306,392

FRICTION ABS ORBING DEVICE Filed Dec. 1.5, 19:58

4 Sheets-Sheet 2 Dec. 29, 1942.. D. M. LIGHT FRICTION ABSORBING DEVICE Filed Dec. 15, 1938 r 4 Sheds-Sheet s I INVENTOR.

flawd/yaghi,

ATTORNEY.

BYQ

D. M. LIGHT 2,306,392

FRICTION ABSORBING DEVICE Filed D60. 15, 1938 4 Sheets-Sheet 4 I -1NVEIYTOR- BY fiawdmlglz ATTORNEY.

tion absorption.

Patented Dec. 29,1942:-

asoaasz T OFFICE Rro'rIo ansonnnvc DEVICE I David M. Light, Chicago, 111., asslgnor to Ameria tion of NewJersey can Steel Foundries, Chicago,

111., a corpora- Application December 1-5, 1938, Serial No. 245,946 Has Claims. (01. 267-9) 'lVIy inventionirelates to a friction absorbing device of the type commonly used on railway equipment in Substitution of one or more'coil springs. v .1. Heretofore gr'eat'dimculty has been encountered in'such friction absorbing devices, 01 snubbers' as they are commonly'called, owingtothe extremely limited space available for such adevice in which the friction absorbing requirement is relatively large. 1

I have solved the difliculty by utilizing a single.

resilient means which is operative to expand the device to its normal open position after a c1 osing stroke and is also operative'to maintain the side wedges tightly engaged against the friction surfaces normallyprovided on the top and bottom followers. Heretofore it has'been found necnovel friction absorbing device, the left-half thereof being in elevation and the right half a sectional view in the vertical plane bisecting the device and substantially as indicated by the line essary to utilize one resilient .means ,for urging the top and bottom followers apart after closing andanother resilient means forlurging the side wedges into frictional engagement with said followers.

.made available more space'for the construction v worn away by .the fric- In overcoming this difficulty I have of parts which must be An object of my invention is to devise'afric- I tion absorbing device suitable for use. in replacing the single coilspring in a railway freight 3 My novel device in the embodiment shown herein consists of only five. parts, two, of which l'-l"o'f.Figu 're 2. shown in its expanded form when not under'load. Figure 2 is a top view of the device shown in Figure 1, the lefthalf thereof showing the top plan and the right half showing a sectional view in the horizontal plane bisecting the device and substantially as indicated by the lineZ-Z of Figurel.

Figure 3 is an elevational view of the device shown in Figure 1 with the parts compressed to their maximum, the right. half of the figure being in elevation and the left-half thereof a section' in the vertical plane bisecting the device substantially as' indicated by the line 3-3' of Figured. 1

'Figure4 is a half top plan and half section,

the sectionbeing taken i'n'the horizontal plane bisecting the device undner maximum compression'and substantially as indicated by theline 4-4 of Figure 3. I

Figure 5is a view, half in elevation and half in section, of the fully' compressed device, the

- elevational view being taken from the right as car, said device comprising a sing'le resilient "member. 'Another object of my invention is to devise a friction absorbing device comprising a min.- .imum number of parts of a form-adaptable'for' most efficient and ine'xpensive production.

are duplicates of each other so thatactually the device comprises only three piece parts. v

Myinvention. furthercomprehends a. form of shock absorbing device" employing a single resilient'means capable of expanding in all planes and thereby effective of certain parts with to produce vertical motion novel device contemplates the use of top and bottom follower membersand side wedge members in engagement therewith, and a single re- Sllient element under' compression between allof: said-members afiording a" direct force path which itlis in direct en-'- gagement and horizontal motion of other parts I with which it is also in direct engagement; My to seen in Figure 3 and the section in a vertical plane bisecting the device substantially as indicated by the line 5-5 of Figure 4. r t

Figure 6 is a plan view of the springcap or follower, the left half showing the top plan view and the right half the bottom' plan view thereof.

' Figure'7' is an elevational view, half in sectti'on, of the spring cap, the elevational view being taken from the bottom as seen in Figure 6 and the section being taken in the vertical plane substantially as indicated by the line 1l of Figure 6. 4

Figure 8 is a side elevation taken from the right as s'een in Figure 6, half-in section, the section being taken in thevertical planebisect- 'ing the follower and substantially as indicated bythe line 88 of Figure 6. n

Figure 9 is'a; further sectional view through one wedge engaging friction surface of the folfrom each. of said members to every other thereof.

"My invention 'also"contemplates a "novel form 3 of resilient'means which is capable'of producing Ftheabove mentioned results-F1 a Figure lcis-aa view of'an embodimentof my-as i lower; the section being taken substantially vertically with respect to said surface-and as indicated by the line 99 of Figure 7;

Figure 10 is a plan view of the side wedge, the

left half thereof showing theouter face and the rightv half the inner face thereof.

Q v Figure 11 is a side elevation of the wedge.

In this view the device is- Figure 12 is an-end elevation of the wedge, half section, the section beingtaken in the-plane dicated'at It, t (Figure Describing my novel device in greater detailjit comprises the top and bottom foliowersl, '2 of identical form, each comprising a rectangular cup-like structure flaring slightly toward its open end and somewhat arcuatesor rounded .on i

the outer face as indicated at 6, 6 to provide suitable seating means for the device. Centrally located in the outer wall is the circular recess 8 convenientefor the reception ofv positioningmeansin the form of a lug or other device provided upon the truck member against which the device may be seated. inwardly of the recess 8 is formed the lug lliwhich projects into the cavity. 12 formed on the end of the resilient means: or spring generally indicated at 14, said lug thus serving as a positioning means for the end of said spring. n oppositeside walls 15, I! of the follower are formed the shallow V'- shaped diagonally arranged friction surfaces in v 1), saidfriction surfaces extending entirely across the inner faces of said walls as best seen from the sectional view shown in Figure 9. .Centrally formed on the friction walls at their open end are the retaining lugs I 8, 18, said lugs being received in the centrally formed slots 20, 20 (Figure13) formed on the outer or friction faces of, the side wedge 2|, said lugs having abutment as at 22, 22 against the ends of said slots to retaintheparts in assembly. outwardly of the :friction surfaces 16, I. on the followers are formed the cavities 24 24'receivng the surplus portions of the resilient meanswhen under compression as best seen at 26, 26 in Figure 3. Leading from the cavities 24 are the channels or, slots the operation of casting, said slots conven ently permitting drainage and escape of other extraneous matter. The. side wedge 21 isof the form shown in detail in Figures to 13 and comprises a generally rectangularfiat piece of solid metal having on'its outer face the diagonal y arranged wed e-shaped friction faces 30, 39 complementary in form to the V-shaped friction surfaces I6, I! on the top and bottom followers. 7 The shape ofthe central slot 2ii-is best seen from a considerati n of Fi ures 10 and 12. said slot receiving the positionin lugs 18, I3 of the-followers. The inner face of the wedgeblock 21 ,is of generally cylind ical form, somewhat flattened atthe cent alpo fion. and .arcuate at thetop and bottom as nd cated at 32, 32 to permit the smoo h flowing of the resil ent means 14 under changing loads as the device'is compressed or expands af e comp ession. ,Cent ally formed on said inner face is the oval cavity 34 receiving the lug 36 cent ally formed on the side of the resilient m ans [4 as best seen in the detailviews of Fi u es 14, and of said resilient member. The outer faces of the followersare cored out as indicated at 38 (Figures Zand 5), thus pro- '28, 28, said slots a forming a convenient means of: core removal in pression the device assumes Jecting the outer wall inwardly of the castin for abutment of the expanding resilient means 14 under compression, and so confining the flow of said resilient means 14 to increase its resist- The detail of the resilient means or rubber spring I4 is shown in Figures 14, 15 and 16. The said resilient means consists of a rectangular body ofrubber composition having the beforementioned centrally located positioning means 28, 36 on opposite wedge engaging sides and presenting at its opposite ends the centrally located circular cavities l2, 12 receiving the beforementioned positioning means on the followers.

The central body: of'the rubber block or resilient means'is 'of slightly larger dimensions than the remainder'thereof, the difference being indicated at the ledges 42, 42 where the end portions merge with the central body portion. The said ledges appear only on two sides of the resilient means so that when viewed inthe other elevation as shown in Figure 15 the thickness of the block or width thereofis constant, Radii are formed at all corners and edges except about the positioning lugs as indicated at 42 and 44 for the main body 46. and 4B forthe endjportions, said radii for the end portions being substantially. increased at theextremities thereof as indicated at 48, 48.' .The said radii servetopermit the 'even flowing of the rubber as it is 'compressed into the form shown in Figures 3, 4 and 5 without developing undue stress localizations portion and at which might break down the structure.

In operation, application of a load to my novel shock absorbing device urges the top and bottom followers toward each other, such movement being resisted by the" resilient member which has abntmentwith each ofsaid followers against the end walls thereof. As said followers are compressed they slide along the friction surfaces of the side wedges with which they engage, thus moving the side wedges. toward each other and compressing the central portion of the resilient member, thus adding further resistance to the forces acting to move the end followers together. By this movement the central resilient member is further compressed and it is compelled to flow into -the availablespace untilunder full comthe form best shown in Figures 3, 4 and 5. Upon release of the load the parts "assume the normal position shown in Figure 1., It ,will readily be understood that the amount of distortion of the'resilient member will depend upon' the-load applied, upon the character of the material of which said resilient member is formed, and upon the arrangement of thefriction surfaces determining theamount of frictional absorption engendered thereby. These factors arejall within the control of the designer in mynovel device inasmuch as more space is permitted within the limitations, embodied than is. possible.where other forms of friction elements are availed of.

It is to be understood that I do not wish be limited by the exact embodiment of the device followers, each of ber interposed between said wedges and said followers and urging them into tight engagement, said resilient member being compressible within saiddevice both I of to permit said'followers and said wedges to approach each other respectively as said device is placed under load. v

2. In a friction absorbing device, identical top and bottom followers each having a plurality of tapering internal friction faces, identical side wedges interposed between said followers and having tapering external frictionsurfaces complementary to said faces and inyengagement therewith, and a resilient member interposed between said wedges and followers, said resilient member being compressible and expansible vertically and laterally to urge said followers and vertically and horizontally therewedges into'tight engagement with each other under operative conditions.

3. In a shock absorber, end members in the form of housings having opposed internal friction faces, side Wedges having external friction surface complementary to said faces and in engagement therewith, and a resilient member'compressed between and having abutment with said wedges and end members, said resilient member being free to flow into end cavities of said housings when said device is placed under compression, and positioning means on said resilient member engaging positioning means on said'end members and on said wedges.

4. In a shock absorber, end housings having cavities and diagonal internal friction faces, side wedges having diagonal external friction surfaces engaging said faces, means on said housings engaging means on said wedges to retain said parts in assembly, and a resilient member confined between said housings and said wedgesto retain said device in its expanded form, said member being compressible under load into said cavities and expansible from said'caviti'es as said load is released. I

5. In a friction absorbing device, identical top and bottom followers having internal tapering friction faces, identical lateral wedges, having external friction surfaces in engagement with said faces, and a resilient member abutting said wedges and said followers to urge them into tight engagement, said resilient memberbeing compressible both vertically and laterally to permit said followers and said wedges respectively to approach each other under compression.

6. In a friction absorbing device, top and bottom followers having internal friction faces, lateral wedges having external friction surfaces abutting said faces, and a resilient member having abutment with said wedges and followers to urge them into'tight engagement, said follower frictionfaces being of V-shaped form and said wedge friction surfaces being ofwedge-shaped form complementary to said faces.

7. In a friction absorbing device, top and bottom followers having internal friction faces, lateral wedges having external friction surfaces a resilient member having abutment with said wedges and followers to urge them into tight engagement, said follower friction faces being V-shaped and said wedge friction surfaces being wedge-shaped, said surfaces and faces being of complementary form and hav-. ing slidable engagement with each other.

7 8. In a friction absorbing device, identical top lties in said housings 9. ma shock absorber, end members in the form of housings having opposed internal friction faces, side "wedges having external friction surfaces complementary to saidfaces and in engagementtherewith, and a resilient member comand-having abutment with said wedges and end members, said resilient member being free to flow intoend cavitiesof said hous-j ings when said sion. l

10. In a friction absorbing device, top and bottom followers having internal V-shaped friction faces, lateral side wedges having external wedgeshaped friction faces in engagement with said V-shaped faces, and a resilient member having bearing against saidwedges and followers to'urge device is placed under compres- I them into tight engagement.

11. In a friction wedges interposed having tapering external friction surfacescomplementary to said faces and in engagement therewith. and a resilient member interposed between said wedges and followers, in abutment therewith.

12. In a friction absorbing device, a resilient member expansible both vertically and laterally and comprising a solidbody of material of generally rectangular section and having end portions with corner radii gradually increasing to a maximum at the ends thereof, and positioning means on the sides and ends of said member.

13. In a shock absorber, end housings having internal friction faces, lateral wedges having .external friction surfaces engaging said faces, cavadjacent the ends thereof, and a resilient member abutting said housings and wedges and free to flow into said cavities when said device is placed under load.

14. In'ashock absorber, housings having internalfriction faces, side wedges having external friction surfaces engaging said faces-engaging of said housings and on said wedges to retain said parts in assembly, and a resilient member confined and compressed between wedges in abutment therewith and further compressible as said device is'placed under load. l

15. In a friction absorbing device, top and bottom follower members having internal friction faces, side wedge members having'external friction faces engaging said internal friction .faces, and a. resilient means having bearing against all of said members to urge said members outwardly.

16. In a friction absorbing device, identical top and bottom-followers having internal tapering friction faces, identical lateral wedges having external friction surfaces in engagement with said faces, and a resilient member abutting said wedges and said followers to urge them into tight engagement. I

17. In a friction absorbing device, a resilient member comprising a solid block of material of generally rectangular form, the extremities of said block having corners of radii gradually inmum at the ends thereof.

creasing to a maximumat the ends thereof, and positioning means on.the ends and on opposite sides of said member.

18. In a friction absorbing and comprising a'solid body of ing corner radii gradually increasing to a maximum of metal for frictional wear adjacent said open end.

-21. In a shock tom followers and absorber, pairs of top and botside wedges having compledevice, a resilient member expansible. both vertically and'laterally material of gen-- erally rectangularsection with endportions havmaxiing one of and adapted-to its transverse 30.,In a springunit, a

leastone of which engaging both engaging said axially. of .said unit, ers, and adaptedto said wedging compressible rubber. means becompressed in the direction of its longitudinal axis by said followers and along;

axis by said engaging said, shoes shoes. pair, of followers, at

has .a friction surface, shoes of said. followers and frictionally surface, rubber means extending engaging one of said followassist in supporting a load on said unit, said rubber means being compressed in the direciion of the axis of said unit when the latteris compressed, and means cooperating with said rubber. means greater frictional contact with for f forcing said shoes into said surface when said unit is compressed.

31. In a resilient supporting unit, a pair of followers, shoes engaging both of said followers and frictionaliy engaging "at least one of them,rubber means laterally distortable and engaging at least mentary engaging friction surfaces, ,and a resillent member compressed between, said followers andwedges and further compressible by'abute ment therewith as said device is placed under load..- q

22. In a frictional device, follower members and wedge members having complementary friction surfaces in abutment witheachothenand a single resilient element compressed by and between-all of said members in. and further compressible therebetween as said device is compactedv under; load.

23. In a friction devlce,'a pair of follower members, a pair of side wedge membersysaid wedge and-follower members having frictional surfaces in engagement with each other, and a resilientelement compressed between said memormal position bers innormai position and further compressible 5 therebetween as said device is placed under load.

24. A friction device comprising endfollower members and side wedge members having frictional engagement with each one of said followers and compressible by the same in the direction of the longitudinal axis of said unit when ing said shoes least one of said followersfor resisting the'further compression of said unit.

32. In a-device of the class described, .the cornbination of two'members adapted to have relative movement said members, and

I along barrel-like projection extending towards the other and providing,

rubber block engaged at opposite ends by said two members and acting to resist the approach of shoe located between the I an axis andeachlhaving a aninner friction surface, a

rubber block and each of said friction surfaces,

said block capable of a iimiteddeformationwhen pressed between said members and shoe to cause. the same tion surfaces whereby the force' acting to cause the members to sisted not only its engagement 33. Inafriction, silient member,

absorbing device,.a and a plurality of sets of fricacting on the to bearv againstsaid fricapproach each other will be re-. by the rubberv block but will be additionally resisted by friction of the shoe in with said members;

single re tion elements securedaround said member in other, and a resilientelement compressed between all of :said

members urging them into tight engagement.

25. A friction device comprising end follower members and sidewedge members havingfric- .tional engagement with each other, a resilient I element. compressed between all of said rneminto tight engagement, and inon'said members.

bers urging them terengaging retaining means 26. In a friction absorbing device, a single resilient member; and a plurality. of sets of interlocked friction elements abutting said member and urged into frictional engagement thereby.

27. A resilient unit for use in bolster supporting spring assemblies comprising a lower follower, an upper follower, friction shoes followers, and an expansible resilient element engaged by said shoes and followers.

28. In a. friction spring supporting unit, a pair of chambered followers having inclined wedging faces," friction shoes eachiengasing a wedging face on each follower, tween said'shoes and being adapted to be compressed vertically when said unit is compressed.

29. In a friction spring supporting unit, .a pair of followers, at least one of ciined wedging faces, friction shoes each engagengaging said v abutmenttherewith and urged gagement. thereby...

34...; friction-device comprising end follower members and sidemembershaving frictional engagement withfeach other, and a resilient elemen't' compressed between all of saidmembers urging them into tight engagement.

35. In a friction spring supporting unit, a pair of chambered wedg'ing faces,

' .wedging face on ea pressed by said followers each friction .shoes having inclined ch follower, and means comfollowers and expanding against saidishoes when said unit is compressed for forcing said shoes into frictional contact with said wedging faces.

36. In a friction spring supporting unit, a pair of chambered followers having inclined wedging faces, friction shoes each engaging a wedging face on each follower, a rubber block between said followers and expansible against said shoes and a rubber element bewhich has inwhen said unit isshoes into frictional contact with said-wedging compressed faces, and cooperating means between said followers. and shoes 'fo in said unit whe ames gn;

r positioning said shoes withthe same is released after mwm if." mo'rrrf faces, 1 and an elongated latter. is compressed for forcintofrictional contact with at into frictional eneach engaging a 

